Geriatric Patients Are at a High Risk of Hypokalemia Associated with Yokukansan Preparation: A Retrospective Cohort Study.

Although hypokalemia is an adverse effect of Yokukansan preparation, especially in geriatric patients, its association with age is unclear. We investigated whether age is a risk factor for hypokalemia. This single-center retrospective cohort study, conducted at Tokyo Women's Medical University, Medical Center East between June 2015 and May 2019, included patients who received the Yokukansan preparation. The primary outcome was hypokalemia (serum potassium level:  75 and >80 years but not 65 years and >70 years. Clinicians should assess risk factors and monitor serum potassium levels to avoid hypokalemia associated with the Yokukansan preparation.